Clinical Chemistry
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 53: 1109-1114, 2007. First published April 13, 2007; 10.1373/clinchem.2006.083055
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow 083055.Supplemental Data
Right arrow All Versions of this Article:
clinchem.2006.083055v1
53/6/1109    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Cundy, T.
Right arrow Articles by Davidson, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Cundy, T.
Right arrow Articles by Davidson, J.
Related Collections
Right arrow Endocrinology and Metabolism
(Clinical Chemistry. 2007;53:1109-1114.)
© 2007 American Association for Clinical Chemistry, Inc.

Endocrinology and Metabolism

Bone Formation Markers in Adults with Mild Osteogenesis Imperfecta

Tim Cundy1,a, Anne Horne1, Mark Bolland1, Greg Gamble1 and James Davidson2

1 Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
2 Department of Clinical Biochemistry, Auckland City Hospital, Auckland, New Zealand.

aAddress correspondence to this author at: Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand. Fax 64-9367-7146; e-mail t.cundy{at}auckland.ac.nz.

Background: Plasma concentrations of procollagen peptides are decreased in osteogenesis imperfecta (OI), whereas other bone formation markers may be increased. We examined the utility of combining these markers in the diagnosis of OI in adults.

Methods: We measured plasma concentrations of procollagen-1 N-peptide (P1NP), osteocalcin, and bone alkaline phosphatase in 24 patients with nondeforming OI, 25 patients with low bone mass due to other causes, and 38 age- and sex-matched controls. The discriminant ability of various test combinations was assessed by the construction of ROC curves.

Results: The median (range) ratio of osteocalcin to P1NP was significantly greater in patients with type I OI [1.75 (0.80–3.86)] than in controls [0.59 (0.34–0.90)] and patients with other causes of low bone mass [0.48 (0.05–1.38); P <0.0001]. This ratio allowed nearly complete differentiation between healthy controls and patients with type I OI, but not patients with type IV OI. With a cutoff of 0.97 for osteocalcin:P1NP, the sensitivity and specificity were maximized at 95% (95% CI 76%–100%) and 88% (69%–97%), respectively, for patients with other causes of low bone mass vs those with type I OI only. For patients with other causes of low bone mass vs all OI patients, sensitivity and specificity were 83% (63%–95%) and 88% (69%–97%), respectively. The addition of bone alkaline phosphatase data did not improve the discriminant ability of the osteocalcin:P1NP ratio.

Conclusions: The osteocalcin:P1NP ratio is a sensitive and specific test for type I OI in adults, but it has less utility in the diagnosis of other types of nondeforming OI.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 by the American Association for Clinical Chemistry.